Put new quadrajet carb on 400, (my mechanic). running way to rich. told me he put a 750 but i need a 650 because the heads on the motor are not correct for a 69 400 330 hp motor. sd they are from a less agressive 400 motor. Motor was out and resealed. sd he noticed then. Does that make sense? I like my guy and he has dome a lot of work. Has a good reputation. The previous carb was period correct numbers matching for a 400. Ran well. he sd the base was bad and it was probably re- jetted.

anyone have thoughts on this mystery. I cant pull apart yhe motor at this point.